Rare manifestation of Waldenström macroglobulinemia with acute kidney injury secondary to cast nephropathy in a young woman

Abstract

A 28-year-old Caucasian woman presented with acute kidney injury secondary to cast nephropathy and was diagnosed with Waldenström macroglobulinemia. This was an unusual presentation, as the patient was both young and female. More over renal involvement in Waldenström macroglobulinemia is rare. Histology of this patient revealed the presence of tubular casts and electron microscopic evidence of monoclonal immune deposit disease. Targeted next-generation sequencing of bone marrow revealed a missense mutation in MYD88 (L265 P) along with a nonsense mutation in CXCR4 (S338*) confirming Waldenström macroglobulinemia. After failing to respond to two cycles of bortezomib-based chemoimmunotherapy and a further 2 months of ibrutinib monotherapy, the patient remained dialysis dependent but managed to achieve a partial response with a different chemoimmunotherapy. Following successful stem cell harvesting, she underwent a melphalan-conditioned autologous stem cell transplant to attain a complete remission with hematologic recovery but with persistent renal impairment.